6

Possibly:
The active ingredient is loratidine, a newer antihistamine. Typically it is unusual to be allergic to an antihistamine, however there are more ingredients involved in manufacturing these products. Typically there are binders, fillers, coloring etc. All of these can rarely cause an allergic reaction.
...Read more

9

Variable:
It all depends. What were the allergic symptoms....Skin, breathing, GI tract, cardiac. Usually an allergic reaction can be between 2 hours to 7 days based on the reaction and many other factors.
...Read more

10

Generic:
Both Claritin (loratadine) and Alavert contain the same active ingredient, Loratadine. Claritin (loratadine) is the original brand name for this drug, and Alavert is one of the less expensive generic forms. They should both work the same for most people.
...Read more

11

Yes:
Alavert d is for allergies. Tamiflu (oseltamivir) is to decrease the symptoms and length of time you have a flu. You can take them together, but you usually don't need to since tamiflu (oseltamivir) is only useful if you do have the flu and it is very early in the course and your symptoms are likely from the flu instead of allergies. If you have allergies, it is useless to use tamiflu (oseltamivir).
...Read more

18

You should not:
Alavert is a non-sedating antihistamine (loratadine), which is the same active ingredient as Claritin. Benadryl is also a antihistamine, but causes more sedation than loratadine. The two should not be taken together as they are the same class of medication with similar mechanisms of action. Flonase is a nasal steroid which can be used with either Alavert or Benadryl
...Read more